Microbes, organisms that are a common part of our surroundings, form an integral part of the ecosystems that exist on Earth. Beyond the world we are familiar with is a more expansive and largely unexplored world that exists far below the surface of soil. A new study has revealed the existence of a new group of microbes existing in the deep soil, which, remarkably, have adapted to a crucial process: the purification of drinking water.
Critical Zone of Earth: A Frontier of Exploration
“Earth’s critical zone” is an underground domain that manages fundamental tasks like the purification of water, soil formation, and nutrient cycling. This zone is of immense importance to life on planet Earth but is still lacking in exploration, especially when it comes to its lower parts.
The Depth of the Critical Zone: An Expansive Subterranean Network
“The Critical Zone extends from the tops of trees down through the soil to depths up to 700 feet,” said Michigan State University’s distinguished microbiology and soils expert James Tiedje. As this critical zone is a network of interlinked systems, it is still broadly unexplored. Nevertheless, the zone is extremely valuable as it performs important functions for food supply, the purity of water, and the health of ecosystems.
A New Branch of Life: The Discovery of CSP1-3
The unique phylum of microbes was discovered by researchers while analyzing deep soil samples in Iowa and China, which have notable deep, rich soils. A phylum in biological classification serves as one of the major divisions. This essentially means that the newly discovered microbes undergo a classification higher than species and strains.
Widespread and Ancient: The Evolutionary Journey of CSP1-3
The researchers obtained DNA samples and constructed the phylogenetic tree for CSP1-3. The results from CSP1-3 research suggest that these particular microbes possess an enduring and captivating history. Their ancestors flourished many years ago in various water bodies containing fresh water and even hot springs. They eventually transitioned into soil life and began their journey from the surface of the soil to the deeper, less explored regions.
Thriving in the Dark: An Unexpected Abundance
Perhaps the most surprising finding is that CSP1-3 microbes are not just surviving in this harsh environment, but thriving. “Most people would think that these organisms are just like spores or dormant,” Tiedje said. Contrary to what most people thought, CSP-13’s geothermal ecosystem was active microbiologically and the DNA samples proved it.
Dominant Players: A Microbial Majority
CSP1-3 microbes having the CSP1-3 strains dominating as over half of the microbial community in some soil samples is astonishing to say the least. This overwhelming portion is unprecedented for soil ecosystems. It appears these microbes must have acquired some form of specialization in order to flourish in such an environment.
Nature’s Water Filter: The Role of Deep Soil
The deep layers of soil are incredibly useful when it comes to the natural filtration of water. As the natural filter of the soil is rain, it starts to undergo an array of physical, chemical, and biological healing processes as it trickles down the region’s soil.
The Underground Clean-Up Crew: CSP1-3’s Vital Function
Tiedje described CSP1-3 as “the scavengers cleaning up what got through the surface layer of soil.” The CSP1-3 also serve the purpose of feeding on any lingering nitrogen and carbon that is washed away from the topsoil. During this process, they assist in the cleansing of groundwater that is meant to be stored in the aquifers, which serve as a resource for people’s drinking water.
The Next Challenge: Growing CSP1-3 in the Lab
The problem now is to propagate CSP1-3 microbes in the laboratory. This is particularly challenging because the deep soil ecosystem is hard to mimic in a laboratory setting. Still, considering the evolutionary background of CSP1-3’s ancestors, the researchers are trying to assist in their growth by maintaining high-temperature environments since their ancestors lived in hot springs.
Potential Benefits: Unlocking Nature’s Secrets
Teaching the existence of CSP1-3 and its metabolic activities might have the potential for great impact. Tiedje speculates that these microbes could contain valuable enzymes or metabolic pathways for different purposes. “For instance, we don’t know their capacities for metabolizing tough pollutants, and if we could figure that out, we can help solve one of the Earth’s most pressing problems,” he added.
A New Appreciation for the Unseen: The Wonders Beneath Our Feet
CSP1-3 serves as a reminder for the overlooked microscopic realms towards our deep Critical Zone. As said by Da Vinci, “We know more about the movement of celestial bodies than about the soil underfoot.” This quote has been used over the years by different scholars for centuries to motivate research that AoI is trying to do to describe the intricate nature beneath the surface that remains largely uncharted.
